"Naturalizing Empire" examines processes of U.S. empire- building through a comparative analysis of U.S. American influence in Liberia, Hawai'i, and Nicaragua in the mid- nineteenth century, focusing on cultural representations of agents of empire assuming or imposing different national identities to gain control of territory and establish networks of trade. I consider how issues of naturalization and sovereignty were bound up within different forms of literary and print culture in order to address the imperial and anti-imperial politics of both canonical and non-canonical literature. This dissertation extends recent scholarship in American literary and cultural studies that examines forms of imperialism beyond the framework of the nation-state, focusing on actions distinct from (and even antagonistic to) the U.S. state and its official representatives. I address the relationship between antebellum culture and different imperial formations that involve selectively disclaiming U.S. national identity as well as controlling a politically independent territory as a means of configuring the U.S. as an exception to (and exceptional) empire. Each chapter addresses particular genres of print culture, including the historical romance, sentimentalism, and cultures of sensation. In chapter one I examine sentimental writings about Liberia by Sarah Hale, Harriet Beecher Stowe, and Helen Knight. In this chapter I also examine critiques of colonization in African American literature, specifically Martin Delany's letters, speeches, and fiction. My second chapter focuses on the Pacific historical romances of James Fenimore Cooper and James Jackson Jarves. In contrast to these texts, I also examine the historiography of Native Hawaiian writers David Malo and Samuel Kamakau that challenged the U.S. presence in the Pacific. Finally, chapter three analyzes sensational stories of filibustering in Nicaragua and representations of the filibuster public sphere in the newspaper El Nicaragüense as well as Frank Leslie's Illustrated Newspaper. Taken as a whole, I suggest literary and other cultural representations of national identities and national boundaries, as well as the development of "American" literary genres, are in fact transnational formations that both facilitate and contest different forms of U.S. empire

The modern Antarctic Dry Valleys are locked in a hyper-arid, polar climate that enables the East Antarctic Ice Sheet (EAIS) to remain stable, frozen to underlying bedrock. The duration of these dry, cold conditions is a critical prerequisite when modeling the long-term mass balance of the EAIS during past warm climates and is best examined using terrestrial paleoclimatic proxies. Unfortunately, deposits containing such proxies are extremely rare and often difficult to date. Here, we apply a unique dating approach to tundra deposits using concentrations of meteoric beryllium-10 ((10)Be) adhered to paleolake sediments from the Friis Hills, central Dry Valleys. We show that lake sediments were emplaced between 14-17.5 My and have remained untouched by meteoric waters since that time. Our results support the notion that the onset of Dry Valleys aridification occurred ~14 My, precluding the possibility of EAIS collapse during Pliocene warming events. Lake fossils indicate that >14 My ago the Dry Valleys hosted a moist tundra that flourished in elevated atmospheric CO2 (>400 ppm). Thus, Dry Valleys tundra deposits record regional climatic transitions that affect EAIS mass balance, and, in a global paleoclimatic context, these deposits demonstrate how warming induced by 400 ppm CO2 manifests at high latitudes.

Selective laser sintering (SLS) is an efficient process in additive manufacturing that enables rapid part production from computer-based designs. However, SLS is limited by its notable lack of in-situ process monitoring when compared to other manufacturing processes. We report the incorporation of optical coherence tomography into an SLS system in detail and demonstrate access to surface and sub-surface features. Video frame rate cross-sectional imaging reveals areas of sintering uniformity and areas of excessive heat error with high temporal resolution. We propose a set of image processing techniques for SLS process monitoring with OCT and report the limitations and obstacles for further OCT integration with SLS systems.